Engineering Formulas

Use consistent SI units and check the assumptions behind each formula. The equations below are quick references; component sizing must also account for geometry, material properties, support conditions, operating loads and applicable standards.

Power and torque

For a rotating shaft: P = 2πnT/60, where P is watts, n is revolutions per minute and T is newton-metres. In practical units: T (N·m) ≈ 9550 × P (kW) / n (rpm).

Force, work and pressure

Force: F = m × a. Work: W = F × s. Pressure: p = F/A. Use N, kg, m, Pa and m² consistently.

Rotating systems and beams

Rotational torque: T = J × α, where J is moment of inertia and α is angular acceleration. Bending stress in the elastic range: σ = M × c / I. Beam deflection depends on support and load arrangement.